SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aacc764f1127c4f399c6c304786d26ebdb601c9444056043b06d57cfb6ce77c8' 
  AND token = 'dP+CMhyl5CoWZmOXU4LA5HJJYjJfNgjoEtTSKP7+QRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}